It is often desirable to know when an analog circuit is ready for operation. Many analog circuits receive their operating voltages through differential amplifiers. For example, a System-on-Chip (SOC)'s voltage monitor (VM) circuit may operate with a voltage received from a bandgap reference, which in turn is built using a differential amplifier. As the inventors hereof have recognized, such a bandgap reference should be capable of guaranteeing the VM circuit's safe state until the reference voltage is close to its nominal value. Accordingly, to address these and other concerns, the inventors hereof have developed ready-flag circuitry for differential amplifiers.